Dynamic power reduction requests for wireless communications

ABSTRACT

Methods and systems for controlling uplink (UL) transmission power of a user equipment (UE) electronic device includes determining, using the UE electronic device, that a maximum power availability for a transmission between the UE and a wireless network node is not appropriate to current conditions. Based on the determination that maximum power availability is not appropriate the UE electronic device sends a request to the wireless network node to reduce power for communication with the wireless network node. Based on the request, the UE electronic device communicates at a reduced power level for communications with the wireless network node.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/910,849, entitled “Dynamic Power Reduction Requests for WirelessCommunications,” filed Oct. 4, 2019, and U.S. Provisional PatentApplication No. 62/755,199, entitled “Dynamic Power Reduction Requestsfor Wireless Communications,” filed Nov. 2, 2018, both of which thisapplication incorporates in their entirety for all purposes.

BACKGROUND

The present disclosure relates generally to power reduction requests forwireless communications and using user equipment (UE) to dynamically setthe power level for communications between the UE and a wirelesslyconnected node of a wireless network.

This section is intended to introduce the reader to various aspects ofart that may be related to various aspects of the present techniques,which are described and/or claimed below. This discussion is believed tobe helpful in providing the reader with background information tofacilitate a better understanding of the various aspects of the presentdisclosure. Accordingly, it should be understood that these statementsare to be read in this light, and not as admissions of prior art.

The 3^(rd) Generation Partnership Project (3GPP) defines variousstandards as part of the duties of the collaborative organization. Forexample, 3GPP has defined a 5G New Radio (NR) Frequency Range 2 (FR2)specification that controls how the UE and a Next Generation NodeB (gNB)communicate and sets power levels for the 5G communications. However,this power level may be inappropriate for at least some periods ofoperation for the UE.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of this disclosure may be better understood upon readingthe following detailed description and upon reference to the drawings inwhich:

FIG. 1 is a block diagram of an electronic device used to communicatewith a base node, in accordance with an embodiment of the presentdisclosure;

FIG. 2 is one example of the electronic device of FIG. 1, in accordancewith an embodiment of the present disclosure;

FIG. 3 is another example of the electronic device of FIG. 1, inaccordance with an embodiment of the present disclosure;

FIG. 4 is another example of the electronic device of FIG. 1, inaccordance with an embodiment of the present disclosure;

FIG. 5 is another example of the electronic device of FIG. 1, inaccordance with an embodiment of the present disclosure;

FIG. 6 is a wireless communication cell with a UE connected to a gNB andanother node, in accordance with an embodiment of the presentdisclosure;

FIG. 7 illustrates a flow diagram of a process for the electronic devicesetting a reduced power level for communications between the electronicdevice and the gNB, in accordance with an embodiment of the presentdisclosure;

FIG. 8 illustrates a flow diagram of a process for event-based settingof a reduced power level for communications, in accordance with anembodiment of the present disclosure;

FIG. 9 illustrates a flow diagram of a process for the UE changing anaggregation factor, in accordance with an embodiment of the presentdisclosure;

FIG. 10 illustrates a flow diagram of a process for the UE changing anaggregation factor, in accordance with an embodiment of the presentdisclosure;

FIG. 11 illustrates a flow diagram of a process that may be used toreduce transmission power for the UE by the gNB, in accordance with anembodiment of the present disclosure;

FIG. 12 illustrates a flow diagram of a process used by the UE to signala duty cycle change using RRC messages, in accordance with an embodimentof the present disclosure;

FIG. 13 illustrates a single-entry power headroom report (PHR) MACcontrol element (CE) used in transmission power reduction by the UE, inaccordance with an embodiment of the present disclosure;

FIG. 14 illustrates a lookup table that may be used for the PHR MAC CEof FIG. 13 to determine a power headroom, in accordance with anembodiment of the present disclosure;

FIG. 15 illustrates a lookup table that may be used for the PHR MAC CEof FIG. 13 to determine a maximum output power, in accordance with anembodiment of the present disclosure; and

FIG. 16 illustrates a multiple-entry power headroom report (PHR) MACcontrol element (CE) used in transmission power reduction by the UE, inaccordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

One or more specific embodiments of the present disclosure will bedescribed below. These described embodiments are only examples of thepresently disclosed techniques. Additionally, in an effort to provide aconcise description of these embodiments, all features of an actualimplementation may not be described in the specification. It should beappreciated that in the development of any such actual implementation,as in any engineering or design project, numerousimplementation-specific decisions must be made to achieve thedevelopers' specific goals, such as compliance with system-related andbusiness-related constraints, which may vary from one implementation toanother. Moreover, it should be appreciated that such a developmenteffort might be complex and time consuming, but may nevertheless be aroutine undertaking of design, fabrication, and manufacture for those ofordinary skill having the benefit of this disclosure.

When introducing elements of various embodiments of the presentdisclosure, the articles “a,” “an,” and “the” are intended to mean thatthere are one or more of the elements. The terms “including” and“having” are intended to be inclusive and mean that there may beadditional elements other than the listed elements. Additionally, itshould be understood that references to “one embodiment,” “anembodiment,” “embodiments,” and “some embodiments” of the presentdisclosure are not intended to be interpreted as excluding the existenceof additional embodiments that also incorporate the recited features.

Since conditions may change in and/or around a UE device communicatingusing a protocol specified in the 3GPP BR FR2, the UE may dynamicallyreduce transmission power during operation to match a level suitable forthe conditions. For instance, the UE may set a reduced peak power leveland/or a reduced average power level based at least in part on theconditions. The conditions that may cause the UE to reduce transmissionpower may include approaching/exceeding a temperature threshold (i.e.,overheating) of the UE, approaching/exceeding a regulatory limit onmaximum permissive exposure (MPE) when a human body is in proximity tothe UE, and/or other suitable conditions. To achieve the reduced power,the UE may notify the gNB to reduce transmission power while attemptingto maintain connection in the cell.

As will be described in more detail below, the electronic device 10 maybe any suitable electronic device, such as a computer, a mobile phone, aportable media device, a wearable device, a tablet, a television, avirtual-reality headset, a vehicle dashboard, and the like. Thus, itshould be noted that FIG. 1 is merely an example of a particularimplementation and is intended to illustrate the types of componentsthat may be present in the electronic device 10.

In the depicted embodiment, the electronic device 10 includes anelectronic display 12, one or more input devices 14, one or moreinput/output (I/O) ports 16, a processor core complex 18 having one ormore processor(s) or processor cores, local memory 20, a main memorystorage device 22, a network interface 24, and a power source 25. Thevarious components described in FIG. 1 may include hardware elements(e.g., circuitry), software elements (e.g., a tangible, non-transitorycomputer-readable medium storing instructions), or a combination of bothhardware and software elements. It should be noted that, in someembodiments, the various depicted components may be combined into fewercomponents or separated into additional components. For example, thelocal memory 20 and the main memory storage device 22 may be included ina single component.

As depicted, the processor core complex 18 is operably coupled to thelocal memory 20 and the main memory storage device 22. Thus, theprocessor core complex 18 may execute instruction stored in local memory20 and/or the main memory storage device 22 to perform operations, suchas generating and/or transmitting image data. As such, the processorcore complex 18 may include one or more general purpose microprocessors,one or more application specific processors (ASICs), one or more fieldprogrammable logic arrays (FPGAs), FIG. or any combination thereof.Furthermore, as previously noted, the processor core complex 18 mayinclude one or more separate processing logical cores that each processdata according to executable instructions.

In addition to the executable instructions, the local memory 20 and/orthe main memory storage device 22 may store the data to be processed bythe cores of the processor core complex 18. Thus, in some embodiments,the local memory 20 and/or the main memory storage device 22 may includeone or more tangible, non-transitory, computer-readable media. Forexample, the local memory 20 may include random access memory (RAM) andthe main memory storage device 22 may include read only memory (ROM),rewritable non-volatile memory such as flash memory, hard drives,optical discs, and the like.

As depicted, the processor core complex 18 is also operably coupled tothe network interface 24. In some embodiments, the network interface 24may facilitate communicating data with other electronic devices vianetwork connections. For example, the network interface 24 (e.g., aradio frequency system) may enable the electronic device 10 tocommunicatively couple to a personal area network (PAN), such as aBluetooth network, a local area network (LAN), such as an 802.11x Wi-Finetwork, and/or a wide area network (WAN), such as a 4G or LTE cellularnetwork. In some embodiments, the network interface 24 includes one ormore antennas configured to communicate over network(s) connected to theelectronic device 10. In some embodiments, the electronic device 10 mayutilize dual connectivity in that the electronic device 10 couples to aprimary cell (e.g., LTE or 5G) and a secondary cell (e.g., 4G or 5G NR)of a same cellular service provider and uses either the primary orsecondary cell to receive data via a serving cell.

Additionally, as depicted, the processor core complex 18 is operablycoupled to the power source 25. In some embodiments, the power source 25may provide electrical power to one or more component in the electronicdevice 10, such as the processor core complex 18, the electronic display12, and/or the network interface 24. Thus, the power source 25 mayinclude any suitable source of energy, such as a rechargeable lithiumpolymer (Li-poly) battery and/or an alternating current (AC) powerconverter.

Furthermore, as depicted, the processor core complex 18 is operablycoupled to the I/O ports 16. In some embodiments, the I/O ports 16 mayenable the electronic device 10 to receive input data and/or output datausing port connections. For example, a portable storage device may beconnected to an I/O port 16 (e.g., universal serial bus (USB)), therebyenabling the processor core complex 18 to communicate data with theportable storage device. In some embodiments, the I/O ports 16 mayinclude one or more speakers that output audio from the electronicdevice 10.

As depicted, the electronic device 10 is also operably coupled to inputdevices 14. In some embodiments, the input device 14 may facilitate userinteraction with the electronic device 10 by receiving user inputs. Forexample, the input devices 14 may include one or more buttons,keyboards, mice, trackpads, and/or the like. The input devices 14 mayalso include one or more microphones that may be used to capture audio.For instance, the captured audio may be used to create voicememorandums. In some embodiments, voice memorandums may include asingle-track audio recording.

Additionally, in some embodiments, the input devices 14 may includetouch-sensing components in the electronic display 12. In suchembodiments, the touch sensing components may receive user inputs bydetecting occurrence and/or position of an object touching the surfaceof the electronic display 12.

In addition to enabling user inputs, the electronic display 12 mayinclude a display panel with one or more display pixels. The electronicdisplay 12 may control light emission from the display pixels to presentvisual representations of information, such as a graphical userinterface (GUI) of an operating system, an application interface, astill image, or video content, by display image frames based at least inpart on corresponding image data. For example, the electronic display 12may be used to display a voice memorandum application interface for avoice memorandum application that may be executed on the electronicdevice 10. In some embodiments, the electronic display 12 may be adisplay using liquid crystal display (LCD), a self-emissive display,such as an organic light-emitting diode (OLED) display, or the like.

As depicted, the electronic display 12 is operably coupled to theprocessor core complex 18. In this manner, the electronic display 12 maydisplay image frames based at least in part on image data generated bythe processor core complex 18. Additionally or alternatively, theelectronic display 12 may display image frames based at least in part onimage data received via the network interface 24 and/or the I/O ports16.

As described above, the electronic device 10 may be any suitableelectronic device. To help illustrate, one example of a suitableelectronic device 10, specifically a handheld device 10A, is shown inFIG. 2. In some embodiments, the handheld device 10A may be a portablephone, a media player, a personal data organizer, a handheld gameplatform, and/or the like. For example, the handheld device 10A may be asmart phone, such as any IPHONE® model available from Apple Inc.

As depicted, the handheld device 10A includes an enclosure 28 (e.g.,housing). The enclosure 28 may protect interior components from physicaldamage and/or shield them from electromagnetic interference.Additionally, as depicted, the enclosure 28 surrounds at least a portionof the electronic display 12. In the depicted embodiment, the electronicdisplay 12 is displaying a graphical user interface (GUI) 30 having anarray of icons 32. By way of example, when an icon 32 is selected eitherby an input device 14 or a touch-sensing component of the electronicdisplay 12, a corresponding application may launch.

Furthermore, as depicted, input devices 14 may extend through theenclosure 28. As previously described, the input devices 14 may enable auser to interact with the handheld device 10A. For example, the inputdevices 14 may enable the user to record audio, to activate ordeactivate the handheld device 10A, to navigate a user interface to ahome screen, to navigate a user interface to a user-configurableapplication screen, to activate a voice-recognition feature, to providevolume control, and/or to toggle between vibrate and ring modes. Asdepicted, the I/O ports 16 also extends through the enclosure 28. Insome embodiments, the I/O ports 16 may include an audio jack to connectto external devices. As previously noted, the I/O ports 16 may includeone or more speakers that output sounds from the handheld device 10A.

To further illustrate an example of a suitable electronic device 10,specifically a tablet device 10B, is shown in FIG. 3. For illustrativepurposes, the tablet device 10B may be any IPAD® model available fromApple Inc. A further example of a suitable electronic device 10,specifically a computer 10C, is shown in FIG. 4. For illustrativepurposes, the computer 10C may be any MACBOOK® or IMAC® model availablefrom Apple Inc. Another example of a suitable electronic device 10,specifically a wearable device 10D, is shown in FIG. 5. For illustrativepurposes, the wearable device 10D may be any APPLE WATCH® modelavailable from Apple Inc. As depicted, the tablet device 10B, thecomputer 10C, and the wearable device 10D each also includes anelectronic display 12, input devices 14, and an enclosure 28.

FIG. 6 is a graph of a system 38 including a UE 40 coupled to a gNB 42in a wireless communication cell 44 of a wireless communication network.The UE 40 may be an electronic device, such as the electronic device 10.The gNB 42 sends data to the UE 40 via a downlink 46 while the UE 40sends data to the gNB 42 via an uplink 48. During some communicationbetween the UE 40 and gNB 42, the downlink 46 or the uplink 48 may be atleast partially directed at a person 50. The UE 40 may track exposure ofthe person 50 to ensure that the person 50 is exposed to less than amaximum permissive exposure (MPE). Specifically, the UE 40 may reducepower used in the communications between the UE 40 and the gNB 42.Furthermore, the UE 40 may reduce power for other reasons, such the UE40 overheating and/or other reasons where reduced power below a maximumpower level may be used. For example, power savings may be applied bythe UE 40 at some level below a maximum level upon initiation of a lowpower mode for the UE 40 due manual selection of the mode and/or basedon power available in a battery providing power to the UE 40 being belowa threshold.

The UE 40 may connect to more than one cell using different or the samewireless protocols. For example, as illustrated, the UE 40 connects toanother node 52 with a downlink 54 and an uplink 56 in a cell 58. Thecell 58 and the cell 44 may be provided by a same provider providingdifferent or the same wireless protocols. For instance, the cell 44 mayutilize 5G NR while the cell 58 may utilize 5G NR, 5G, 4G, LTE, WiFi,and/or other wireless protocols.

Reduced Power Levels

With the foregoing in mind, FIG. 7 is flow-diagram of a process 60 thatmay be used by the UE 40 coupled to a network to cause the UE 40 torestrict transmission power in communication between the UE 40 and thenetwork via the gNB 42. The UE 40 determines that a maximum poweravailability for the transmission is not appropriate to the currentconditions (block 62). For instance, the UE 40 may determine that themaximum power availability may be beyond the capabilities of the UE 40,may cause or may have already caused the UE 40 to overheat, may possiblycause a human body to exceed the MPE due to transmissions between the UE40 and the gNB 42, and/or other conditions. The UE 40 then sets a lowerpower level that is lower than the maximum power availability (block64). For instance, the UE 40 may enable discontinuous transmissions(DTX), set a duty cycle for the transmissions, and/or increase slotaggregation. The UE 40 then operates at the lower power level (block66).

Event-Based Power Restriction

During operation, the UE 40 may track one or more conditions, such heatlevel of the UE 40, available power for the UE 40 from its battery,exposure to transmissions by the person 50, and the like. When an eventoccurs such that a condition of the one or more conditions exceeds acorresponding threshold, the UE 40 may adjust a power level of atransmission between the UE 40 and the gNB 42. FIG. 8 is a flow-diagramof a process 110 for event-based power restriction. The UE 40 determineswhether an event has occurred (block 112). For instance, the event maycorrespond to the UE 40 overheating, a limit on UE 40 output powerrestricted due to MPE limits, use of battery power by the UE 40 and anamount of charge of the battery being below a threshold, and/or othersituations where transmit power is to be reduced for the UE 40.

Once such an event occurs, the UE 40 determines whether DTX is activatedfor communications with the gNB 42 (block 114). When DTX is notactivated, the UE 40 activates DTX with a desired duty cycle suitablefor the event (block 116). For example, the duty cycle may beproportional to underlying properties of the event. For instance, if theUE 40 has/is overheating by a first value, a first duty cycle may beused. However, if the UE 40 has overheated or is overheating by a secondand higher value, a second duty cycle that is lower than the first dutycycle may be used. Similarly, detection of a person in a direct pathbetween the UE 40 and gNB 42 may cause the UE 40 to use a lower dutycycle than detection of the person close enough to be partially exposedto the communications.

If DTX is already activated, the UE 40 determines whether a current dutycycle for the DTX is less than or equal to a target duty cycle (block118). If the current duty cycle is less than or equal to the target dutycycle, the UE 40 continues operation at the current duty cycle (block120). If the current duty cycle is greater than the target duty cycle,the UE 40 lowers the duty cycle (block 122).

In some embodiments, the UE 40 may continuously track the event or mayset a period for reduced power. The UE 40 may determine whether theevent or time has lapsed (block 124). Once the time for reduced powerhas lapsed, the UE 40 restores the duty cycle from before the event(block 126). The restored duty cycle may include a previous duty cycleor may include a 100% duty cycle (e.g., returning to continuoustransmissions).

Static Duty Cycle Capability-Based Restriction

A capability of the UE 40 is defined in the specification to allow theUE 40 to request a static scheduler restriction on the network tomaintain the percentage of allocated UL symbols over a certainevaluation period. For instance, the UE 40 may set a maxUplinkDutyCyclecapability with percentage values (e.g., 60, 70, 80, 90, or 100) in thespecification. If the maxUplinkDutyCycle capability is not signaled tothe gNB 42 (or other node in the network), there is no restriction on ULsymbol scheduling. If this capability is signaled, a restriction on ULsymbol scheduling is applied according to this capability. If thiscapability is signaled, and the percentage of UL symbols allocated tothe UE 40 exceeds the capability, then the UE 40 calculates and appliesa power reduction via a power back-off (e.g., P-MPR) to the gNB 42. Thispower reduction value may be set at any percentage value (e.g., 10, 20,30, 40, 50, 60, 70, 80, 90, and 100 percent) of the maximum power.

Event-Triggered Duty Cycle Restriction

The UE 40 may utilize an uplink duty cycle restriction. The uplink dutycycle restriction is defined as a scheduler restriction on the network(via the gNB 42) to maintain a percentage of allocated uplink symbolsfor the UE 40 over a certain evaluation period. For instance, the valuesmay be 10 percent, 20 percent, 30 percent, 40 percent, 50 percent, 60percent, 70 percent, 80 percent, 90 percent, or another percent.Furthermore, different uplink duty cycle restrictions may be tied todifferent levels of the parameter corresponding to the event. Forexample, different thresholds of overheating of the UE 40 may correspondto different duty cycle restrictions. Similarly, different duty cyclelevels may be selected for different thresholds of other event types.

When the event occurs, the UE 40 sends the event-triggered request tothe network (via the gNB 42) with additional event reported information.If the event corresponds to the UE 40 overheating, the UE 40 transmitsthe event trigger to the network with the reported information of atarget UL duty cycle and/or power back-off (P-MPR). If the eventcorresponds to the UE 40 limited due to MPE, the UE 40 transmits theevent trigger to the network with the reported information of a targetuplink duty cycle and/or a P-MPR to meet MPE limits. Similarly, the UE40 may send communications for other event types that specific a targetuplink duty cycle and/or a P-MPR. The UE 40 may track the event and/oruse a timer to set a duration of reduced transmission power. In the caseof a timed duration of reduced transmission power, the UE 40 maytransmit an indication of the duration to the network and/or may trackthe duration with a timer and send a notification after the duration ofthe reduced transmission power has elapsed. In some embodiments, toenable UE implementation flexibility in meeting MPE limits or othertransmission power thresholds, the UE 40 may change the event parametersthat lead to the triggers, such as select a different uplink duty cyclerestriction or remove the duty cycle restriction for certain eventsand/or levels associated with events.

Event-Triggered Uplink Slot Aggregation

In addition to or alternative to duty cycle manipulation, the UE 40 maychange an aggregation factor based on the events. FIG. 9 is a flowdiagram of a process 130 for the UE 40 changing an aggregation factor.The UE 40 detects an event (block 132). When the event is detected, theUE 40 sends an event-triggered request to the gNB 42 to change anaggregation factor for the transmission (block 134). For instance, theUE 40 may send a desired Physical Uplink Shared Channel(PUSCH)-AggregationFactor for each bandwidth part (BWP) of links betweenthe UE 40 and the gNB 42. In some embodiments, the UE 40 may send anexpected duration for the requested change as part of the request.

Subsequently, when the UE 40 is granted with an uplink transmission, theUE 40 repeats the PUSCH in multiple consecutive time allocations with areduced power (block 136). For instance, the aggregation factor maycombine a number of time slots that reduces power consumption to a levelapproximately inversely proportional to the PUSCH-AggregationFactor. Forinstance, when the PUSCH-AggregationFactor is doubled (e.g., set to 2from no aggregation), the power consumption is reduced by half.

When the criteria of such an event is no longer met, the UE 40 may sendan event-triggered request to disable UL slot aggregation (block 138).Additionally or alternatively, when the duration of the UL slotaggregation request has passed, the gNB 42 may disable UL slotaggregation (and send a TPC command) without a later request from the UE40 after the initial aggregation request.

FIG. 10 is a flow diagram of a process 140 performed by the gNB 42and/or other device in the network with a slot aggregation factorchange. The gNB 42 receives the request from the UE 40 (block 142). Uponreceiving the request, the gNB 42 sends a PUSCH-Config for each activeBWP with the PUSCH-AggregationFactor set to the appropriate value (block144). The gNB 42 may then send transmission power control (TPC) commandsto reduce the transmission power according to the number of aggregateduplink slots to maintain a combined signal quality (block 146). The gNB42 then receives repeated uplink signals across slots (block 148). ThegNB 42 may end using the reduced transmission power (block 150). To endthe reduced transmission power, the gNB 42 may receive a message fromthe UE 40 that the period of reduced power has ended due to a change inparameter corresponding to the event or a timer associated with thereduced transmission power elapsing. Additionally or alternatively, theoriginal request from the UE 40 may have an indication of a duration forthe reduced transmission power, and the gNB 42 may track the duration ofthe reduced transmission period to stop using reduced transmission powerafter the duration has elapsed.

UE Initiates Transmission Power Reduction

As previously discussed, the UE 40 may autonomously reduce its ownmaximum transmission power. For example, the UE 40 may apply the powerback-off (P-MPR) according to MPE safety constraints, temperature of theUE 40, and/or other events. However, transmission power reduction maycreate issues for communications between the UE 40 and the gNB 42 byimpacting UL coverage. Furthermore, since P-MPR is a mechanism driven byand controlled by the UE 40, the network has no explicit indication onthe reduced transmission power that may worsen propagation conditions.As discussed below, the UE 40 may send indications of self-reductions tothe gNB 42. For instance, a power headroom report (PHR) may include a“P” field that indicates that P-MPR is applied.

Large P-MPRs may degrade the link too much. Indeed, a large P-MPR maycause radio link failure between the UE 40 and the gNB 42 followed by aradio resource control (RRC) re-establishment process.

In addition to or alternative to P-MPR, the UE 40 may invoke a reducedUL duty cycle, as previously discussed. Unlike P-MPR, a reduced dutycycle may prevent a UE 40 from reducing its transmission power becauseit can continue transmitting at the same level due to the fact that thenetwork does not allocate UL grants in every available period. Eventhough the reduced duty cycle approach may ensure better UL coverage,the reduced duty cycle may negatively impact the achievable throughputin the UL. Since the maximum UL duty cycle is a static UE capability,the network may not know when a reduced duty cycle may be appliedwithout communication from the UE 40. Accordingly, a most conservativenetwork implementation may always schedule the UE 40 accordingly.Furthermore, even if a UE 40 signals a very conservative maximum UL dutycycle value (e.g. 20% duty cycle), the power adjustment may beinsufficient causing the UE 40 to invoke P-MPR for further powerreduction.

Bit Repurposing Power Reduction for Slot Aggregation

In a self-reduction by the UE 40, the PHR may be triggered when aPHR-prohibit-timer expires. In the PHR, a large negative power headroom(PH) may be reported and a reduced and targeted maximum allowed transmitpower (Pcmax) may be used.

In some cases, the reduced power may be insufficient to maintain theuplink connection without slot aggregation and/or may be insufficient tokeep the UE 40 temperature (or other parameters) under a respectivethreshold value. In such situations, bits in the communications reservedfor PH and Pcmax may be repurposed to indicate various parameters toassist the network in reducing power usage for the UE 40. For example,the bits (e.g., 4 bits) may each include a flag. For instance, a firstflag may indicate whether the UE 40 is overheating, a second flag mayindicate whether an MPE restraint exists, a third flag may indicatewhether a request is made to reduce a duty cycle of the communication,and/or a fourth flag may be used to enable uplink slot aggregation. Theflagged values may also be followed by other actions. For example, theUE 40 may send the uplink slot aggregation request and/or duty cyclechange request as previously discussed.

In some embodiments, the bits may use one or more (e.g., 2) bits toindicate a target level of uplink slot aggregation. For instance, insome embodiments, the bits may indicate a value, n, and the aggregationfactor may be 2″. Additionally or alternatively, a number of bits may beused to indicate a desired duty cycle, or duty cycle reduction.Additionally or alternatively, the bits may be used to indicate otherpower reduction parameters.

Communicating an Amount of Power Reduction

The UE 40 monitors the amount of emitted power in an uplink within amoving window of time. If the total emitted power exceeds a threshold,the UE 40 may inform the gNB 42 by sending an RRC message. Accordingly,the UE 40 may request the network to decrease its duty cycle to reducepower of the transmission. In response, the network may allocate fewerresources to the UE 40 for a period of time. In some embodiments, thenetwork may choose a fixed duration for duty cycle restriction based onFCC regulation. Additionally or alternatively, the UE 40 may inform thegNB 42 about an appropriate duration for duty cycle restriction.

As previously noted, the UE 40 initiates the power reduction and maysend an indication (e.g., “P” field in the PHR) that the power reductionis greater than a threshold (e.g., 3 dB). However, even with thisindication, the network may not be aware of an amount of power reductionwithout information from the UE 40 indicating an amount of powerback-off (e.g., 3 dB or 6 dB). The network may use this information tooptimize network-side scheduling.

In some embodiments, the network (e.g., gNB 42) may decide how toachieve a power reduction in response to the request from the UE 40.FIG. 11 illustrates a flow diagram of a process 200 that may be used toreduce transmission power for the UE 40 by the gNB 42. The gNB 42receives the request from the UE 40 to reduce transmission power via aP-MPR (block 202). Instead of applying a reduced transmission power byreducing transmission levels, the network (e.g., the gNB 42) may atleast partially convert the reduction to a duty cycle reduction (block204). For instance, if the indicated power back-off is a percentagereduction (e.g., 3 dB), the network may cause communications with the UE40 to be reduced by a percentage (e.g., 75% duty cycle). Furthermore,the network may apply a duty cycle and/or a power level transmissionreduction. For instance, if a higher power factor change (e.g., 6 dB) isindicated, the network may reduce the duty cycle while power of the peaktransmission power during the duty cycle is also reduced.

Radio Resource Control (RRC) Signaling

The UE 40 may utilize RRC signaling to provide assistance information toaid the network in scheduling communications with the gNB 42. In someembodiments, the UE 40 may repurpose an RRC message or create new RRCmessages, RRCAssistanceInformation or UEAssistanceInformation, toinclude new information elements (IE) to inform the network aboutvarious issues, such as an overheating problem at UE 40, MPE issues, andthe like. The RRC message may indicate a delay budget and RRCconfiguration for various scenarios (e.g., overheating, MPE, etc.)and/or may indicate a target UL duty cycle.

FIG. 12 is a flow diagram of a process 210 used by the UE 40 to signal aduty cycle change using RRC messages. The UE 40 detects a parametercrossing a threshold (block 212). As previously discussed, the parametermay be related to MPE, overheating, available power, battery usage,and/or other aspects of operation of the UE 40. Based at least in parton the passed threshold, the UE 40 determines that P-MPR is to beapplied (block 214). The UE 40 then requests an allocation to send theRRC signal to the gNB 42 (block 216).

Since performing RRC communications uses network resources, the UE mayhave a timer that controls how frequently the request may be sent or theRRC exchange may be used. If the timer has expired, the UE 40 mayre-send the request. Otherwise, the UE 40 may suppress sending therequest to initiate the RRC exchange until the timer elapses.

The UE 40 receives the allocation (block 218) and sends the RRC messageto the gNB 42 during the allocation (block 220). As previously noted,the RRC message includes assistance information detailing informationabout the parameter, the duty cycle, and/or the P-MPR. The RRC messagemay include other information, such as device capability changes and thelike. The network makes a decision on how to perform the powerreduction. For instance, as previously discussed, the network may decidethat a duty cycle is to be used to reduce transmission power rather thandecreasing transmission power levels for the UE 40 to prevent degradingUL coverage. Alternatively, the network may choose to decrease thetransmission power by reducing transmission levels to prevent a loss inUL throughput. The UE 40 receives an indication from the networkinstructing how to implement the power reduction from the gNB 42 (block222) and reduces power according to the indication (block 224).

The additions of the new IEs for the parameters may be added easilyregardless of size or structure of the assistance data. Indeed, all ofthe IEs may be encoded in single specification for simplicity. However,since the RRC exchange involves waiting on an allocation of networkresources, the RRC-message-based communication of assistance informationto the network may be susceptible to delays especially in heavily loadednetworks. In time sensitive-settings, an alternative solution forcommunicating the assistance information may be utilized: 1) extending apower headroom report (PHR) MAC control element (CE) to include theassistance information or 2) adding a new PHR MAC CE to include theassistance information.

A Single-Entry PHR MAC CE

An existing PHR MAC CE may be enhanced to include the assistanceinformation (e.g., MPE assistance information) in a single entry inaddition to the “P” field. Since the network may utilize an existing PHRMAC CE, the addition of the assistance information may be selectivelyenabled by the network to ensure that the potential inclusion of theassistance information would not interfere with legacy PHR MAC CEoperations. Furthermore, the actual presence of the assistanceinformation may be linked to the existing “P” field of the PHR such thatthe assistance information is added anytime P-MPR is invoked.

The single-entry PHR MAC CE may be identified by a MAC subheader using alanguage code identifier (LCID). The single-entry PHR MAC CE may have afixed or dynamic size. For example, FIG. 13 illustrates a three-octetfixed length for the single-entry PHR MAC CE. Alternative embodimentsmay include any other suitable length for the single-entry PHR MAC CE.As illustrated, the single-entry PHR MAC CE may include reserved bits250 that may be set to known values (e.g., 0) and/or reserved for use inother applications. The single-entry PHR MAC CE includes a powerheadroom (PH) field 252. The PH field 252 indicates the power headroomlevel for the UE 40. The length of the field may be any suitable length(e.g., 6 bits). The reported PH in the PH field 252 may be used todetermine the corresponding power headroom levels by using a lookuptable that is indexed using the bits in the PH field 252, such as lookuptable 254 in FIG. 14. In the illustrated lookup table 254, the length ofthe PH field 252 is 6 bits enabling the PH field 252 to specify 64different PH levels. Different numbers of bits in the PH field 252 mayenable specifying a different number of PH levels.

Returning to FIG. 13, the single-entry PHR MAC CE also may include aP_(CMAX,f,c) field 256. The P_(CMAX,f,c) field 256 indicates the maximumoutput power (P_(CMAX,f,c)) for a carrier of a serving cell (e.g., aprimary cell (Pcell) or secondary cell (Scell)) for the UE 40. TheP_(CMAX,f,c) used for calculation of the preceding PH field 252. Eachpossible reported P_(CMAX,f,c) value may correspond to a respectivenominal UE 40 transmit power level. FIG. 15 shows a table 258illustrating an example relationship between the P_(CMAX,f,c) values andthe respective nominal transmit power levels. The corresponding measuredvalues of the table 258 may be measured in dBs and specified in aspecification for the physical layer procedures for control in 5G NR.

Returning to FIG. 13, the single-entry PHR MAC CE includes an optionalassistance information field 260 that may be utilized based on networkconfiguration. If present, assistance information field 260 indicatesactual power back-off applied by the UE due to MPE, overheating, poweravailability, battery usage, and/or other parameters. As illustrated,the assistance information field 260 is an octet of data that may beused to encode an actual power back-off value.

In some embodiments, the assistance information field 260 may be omittedwith the PHR MAC CE instead utilizing two or more of the reserved bits250 to indicate one of an enumerated list of possible values the powerback-off. The meaning of these values may vary depending on a set powerfactor change in the PHR configuration. In other words, a power factorchange may be set in the PHR configuration that controls which lookuptable is used to convert the values in the assistance information field260 into an actual power reduction. Thus, the power reduction is basedon the set power factor change and the value in the assistanceinformation field 260. For example, the power factor change may beselected as a reduction of dB3 from an enumerated list of reductions bydB1, dB3, or dB6. A LUT corresponding to dB3 is used to determine anamount of back-off based on the value in the assistance informationfield 260. For example, if the assistance information field 260 uses twoof the reserved bits 250 for the LUT, the value in the assistanceinformation field 260 may be used to select one of four availableback-offs of the transmission power as transmission level reductionsand/or duty cycle reductions.

By utilizing an existing PHR MAC CE, the existing framework for PHR maybe changed by a little to deliver messages faster than may be deliveredvia the RRC-based framework. However, extending the PHR MAC CE is morecomplicated that adding the new IEs used in the RRC-based framework. ThePHR MAC CE is also limited (e.g., 8 bits) in the amount of informationthat may be transferred via the MAC CE.

Multiple-Entry PHR MAC CE

Instead of using an existing PHR MAC CE, a new PHR MAC CE may beintroduced. In the new PHR MAC CE, the P-MPR assistance information maybe included. Due to the octet alignment of existing MAC CE elements, thenew PHR MAC CE may include an 8-bit field for the assistance informationfield 260. With the introduction of a new PHR MAC CE, the new PHR MAC CEmay be independent from an existing PHR MAC CE to which the new PHR MACCE is not linked.

As illustrated in FIG. 16, the new PHR MAC CE may have a variable size.The new PHR MAC CE includes PH fields 252 and P_(CMAX,f,c) fields 256for a special cell, the Pcell, and one or more serving cells. Thespecial cell refers to the Pcell of a master cell group or a primarysecondary cell of a secondary cell group. The new PHR MAC CE alsoincludes cell index flags 270, 272, 274, 276, 278, 280, and 282 thateach indicates whether a corresponding PH field 252 and P_(CMAX,f,c)field 256 is included in the PHR MAC CE for serving cells. For instance,C₁ flag 282 set to a first value (e.g., 1) indicates that the PH field252C is reported while the C₁ flag 282 set to a second value (e.g., 0)indicates that the PH field 252C is not reported in the PHR MAC CE.Similarly, the remaining serving cells each have their own flags and maybe similarly signaled. Although the illustrated embodiment of the newPHR MAC CE includes a single octet bitmap to indicate the presence of PHfields 252 for the serving cells using the flags, additional octets(e.g., total 4 octets) when more than 8 uplinks are configured for theUE 40.

The PH field 252A for the special cell is Type 2 PH field that may beconfigured separately than Type 1 PH fields (e.g., PH field 252B). Theserving cells correspond to Type X PH fields that may be Type 1 PHfields or a separately configured Type 3.

The MAC entity determines whether the PH value for an activated ServingCell is based on real transmission or a reference format by consideringthe configured grant(s) and downlink control information. The downlinkinformation is received until and including when the physical downlinkcontrol channel (PDCCH) first UL grant for a new transmission that canaccommodate the MAC CE for PHR is received. The first UL grant causes aPHR to be triggered if the PHR MAC CE is reported on the UL grantreceived on the PDCCH. Additionally or alternatively, the downlinkinformation may be received until the first UL symbol of a physicaluplink shared channel (PUSCH) transmission minus PUSCH preparation timeif the PHR MAC CE is reported on already configured grant.

For a band combination in which the UE 40 does not support dynamic powersharing, the UE 40 may omit the octets containing the PH field 252 andP_(CMAX,f,c) field 256 for Serving Cells in other MAC entities exceptfor the PCell in the other MAC entity. The reported values of PH andP_(CMAX,f,c) for the PCell are up to implementations of the UE 40.

As illustrated in FIG. 16, the new PHR MAC CE includes reserved bits 250that may be used to transmit the assistance information for each cell.Alternatively, separate assistance information fields 260 in a differentoctet may be used transmit the assistance information. Similarly, thePHR MAC CE may include a pair of the PH field 252 and the P_(CMAX,f,c)field 256 for each cell.

The new PHR MAC CE may also include a V field 284 that indicates whetherthe PH value is based on a real transmission or a reference format. ForType 1 PH fields (e.g., PH field 252B), the V field 284 is set to afirst value (e.g., 0) that indicates that the value is based on a realtransmission on PUSCH, and the V field 284 set to a second value(e.g., 1) indicates that the PUSCH reference format is used. For Type 2PH fields, the V field 284 set to the first value (e.g., 0) indicatesreal transmission on a physical uplink control channel (PUCCH), and theV field 284 set to the second value (e.g., 1) indicates that a PUCCHreference format is used. For Type 3 PH, the V field 284 set to thefirst value (e.g., 0) indicates real transmission on sounding referencesignals (SRS), and the V field 284 set to 1 indicates that an SRSreference format is used. Furthermore, for Type 1, Type 2, and Type 3PHs, the V field 284 set to the first value (e.g., 0) indicates thepresence of the octet containing the associated P_(CMAX,f,c) field 256,and the V field 284 set to the second value (e.g., 1) indicates that theoctet containing the associated P_(CMAX,f,c) field 256 is omitted.

The new PHR MAC CE may also include a P field 286 that indicates whetherthe MAC entity applies power back-off due to power management (asallowed by P-MPR_(c)). The MAC entity sets the P field 286 to a firstvalue (e.g., 1) if the corresponding P_(CMAX,f,c) field 256 would havehad a different value if no power back-off due to power management hadbeen applied.

As may be appreciated, the RRC-based architecture may be deployed insome networks due to the simplicity of deployment relative to the PHRMAC CE while either of the PHR MAC CE-based schemes may be used inarchitectures where timeliness is preferred over simplicity ofdeployment.

The specific embodiments described above have been shown by way ofexample, and it should be understood that these embodiments may besusceptible to various modifications and alternative forms. It should befurther understood that the claims are not intended to be limited to theparticular forms disclosed, but rather to cover all modifications,equivalents, and alternatives falling within the spirit and scope ofthis disclosure.

The techniques presented and claimed herein are referenced and appliedto material objects and concrete examples of a practical nature thatdemonstrably improve the present technical field and, as such, are notabstract, intangible or purely theoretical. Further, if any claimsappended to the end of this specification contain one or more elementsdesignated as “means for [perform]ing [a function] . . . ” or “step for[perform]ing [a function] . . . ”, it is intended that such elements areto be interpreted under 35 U.S.C. 112(f). However, for any claimscontaining elements designated in any other manner, it is intended thatsuch elements are not to be interpreted under 35 U.S.C. 112(f).

What is claimed is:
 1. A method, comprising: determining, using a userequipment electronic device (UE), that a maximum power availability fora transmission between the UE and a wireless network node is notappropriate to current conditions; sending, using the UE, a request tothe wireless network node to reduce power for communication with thewireless network node, wherein the request comprises a request to changean aggregation factor to increase slot aggregation for communicationswith the wireless network node; and communicating, using the UE, at areduced power level for the communications with the wireless networknode.
 2. The method of claim 1, wherein the wireless network nodecomprises a Next Generation NodeB (gNB).
 3. The method of claim 1,wherein sending the request further comprises sending UE capabilitiesfor the UE to indicate the reduced power level.
 4. The method of claim3, wherein the UE capabilities are set by determining the maximum poweravailability is inappropriate prior to establishing communication withthe wireless network node.
 5. The method of claim 1, wherein determiningthe maximum power availability is not appropriate comprises determiningwhether an event occurs during communication between the UE and thewireless network node.
 6. The method of claim 5, wherein the eventcomprises the UE overheating.
 7. The method of claim 5, wherein theevent comprises that a human body has entered into proximity of the UEin a communication path between the UE and the wireless network node andthe human body is likely to be exposed to wireless signals above amaximum permissive exposure (MPE) limit unless the reduced power levelis used.
 8. The method of claim 1, wherein the reduced power levelcomprises a reduced duty cycle for uplink communications between the UEand the wireless network node.
 9. The method of claim 1, wherein thereduced power level comprises a reduced peak power used in uplinkcommunications between the UE and the wireless network node.
 10. Anelectronic device, comprising: one or more antennas configured tocommunicate with one or more wireless network nodes; one or moreprocessors; memory storing instructions that, when executed by the oneor more processors, are configured to cause the one or more processorsto: request, via the one or more antennas, a power reduction for anuplink to a wireless network node of the one or more wireless networknodes below a maximum transmission level, wherein the request is sentvia a radio resource control (RRC) message, and wherein the requestcomprises a request to change an aggregation factor to increase slotaggregation for communications with the wireless network node; receivean indication from the wireless network node comprising instructions onhow to reduce power; and reduce transmission power based at least inpart on the instructions.
 11. The electronic device of claim 10, whereinthe instructions, when executed by the one or more processors, areconfigured to cause the one or more processors to: detect a parameterfor the electronic device surpassing a threshold; and based on thesurpassed threshold, determine that a power back-off is to be requested,wherein requesting the power reduction is based at least in part on thedetermination that the power back-off is to be requested.
 12. Theelectronic device of claim 11, wherein the parameter comprises atemperature for the electronic device, exposure of a person in a path ofthe uplink, or amount of power available for the electronic device; orany combination thereof.
 13. The electronic device of claim 10, whereinrequesting the power reduction comprises: requesting an allocation fromthe wireless network node to send the RRC message; and sending the RRCmessage during an allocated slot.
 14. The electronic device of claim 10,wherein requesting the power reduction further comprises a powerback-off signal having an indication of an amount of reduction of peaktransmission power levels for the electronic device.
 15. The electronicdevice of claim 14, wherein the indication from the wireless networknode at least partially converts the power back-off signal from theamount of reduction of peak transmission power levels to a reduced dutycycle.
 16. The electronic device of claim 10, wherein the RRC messagecomprises assistance information indicating an amount of power reductionfor the uplink.
 17. Tangible, non-transitory, and computer-readablemedium having stored thereon instructions, that when executed by aprocessor, are configured to cause the processor to: determine that aparameter of a user equipment (UE) device has crossed a threshold; basedon the parameter crossing the threshold, determine that a powerreduction is to occur; and send a request, via an antenna, to a wirelessnetwork node of a wireless network to reduce transmission power for theUE device to the wireless network node, wherein the request is includedin a power headroom report (PHR) for the wireless network, and whereinthe request comprises a request to change an aggregation factor toincrease slot aggregation for communications with the wireless networknode.
 18. The tangible, non-transitory, and computer-readable medium ofclaim 17, wherein the request comprises assistance informationindicating a degree of transmission power reduction.
 19. The tangible,non-transitory, and computer-readable medium of claim 18, wherein theassistance information is included in a PHR MAC control element (CE)with a single entry of a PHR for a single cell of the wireless network.20. The tangible, non-transitory, and computer-readable medium of claim18, wherein the assistance information is included in a PHR MAC controlelement (CE) with a multiple entries of PHRs for various wirelessnetwork cells.